docs: copyedit quickstart (#3105)

Copyedit Quickstart's title, subtitle, and initial paragraph to
introduce GraphOS and supergraph

Author: shorgi

docs/source/quickstart.mdx

@@ -1,10 +1,10 @@
 ---
-title: Apollo Federation Quickstart
-subtitle: Build a federated GraphQL API with Apollo Federation
-description: Build a federated GraphQL API with Apollo Federation
+title: Apollo GraphOS Quickstart
+subtitle: Build a federated GraphQL API with Apollo Federation and GraphOS
+description: Build a federated GraphQL API with Apollo Federation and GraphOS
 ---
 
-Apollo Federation combines microservices into a single GraphQL API, providing real-time access to all your data sources for all your client applications.
+Apollo Federation combines microservices into a single GraphQL API, providing real-time access to all your data sources for all your client applications. Apollo GraphOS is the platform for building, testing, and deploying a federated GraphQL API—also known as a supergraph.
 
 ```mermaid
 graph LR;
@@ -26,7 +26,7 @@ graph LR;
   class iot secondary;
 ```
 
-By the end of this quickstart, you'll have set up a federated GraphQL API—also known as a _supergraph_—that integrates data from products, users, and inventory services.
+By the end of this quickstart, you'll have set up a supergraph that integrates data from products, users, and inventory services.
 Along the way, you'll learn about tools like the Rover CLI and GraphOS Studio.
 
 To learn more about Apollo Federation and the benefits of using it with GraphOS, check out these resources: